#pragma once

#include "net.hpp"
#include "message.hpp"

namespace gmrpc
{

    class Callback
    {
    public:
        using ptr = std::shared_ptr<Callback>;
        virtual void onMessage(const BaseConnection::ptr &conn, BaseMessage::ptr &msg) = 0;
    };

    template <typename T>
    class CallbackT : public Callback
    {
    public:
        using ptr = std::shared_ptr<CallbackT<T>>;
        using MessageCallback = std::function<void(const BaseConnection::ptr& conn,std::shared_ptr<T>& msg)>;
        CallbackT(const MessageCallback &handler) : _handler(handler)
        {
        }

        void onMessage(const BaseConnection::ptr &conn, BaseMessage::ptr &msg) override
        {
            auto type_msg = std::dynamic_pointer_cast<T>(msg);
            _handler(conn, type_msg);
        }

    private:
        MessageCallback _handler;
    };

    class Dispatcher
    {
    public:
        using ptr = std::shared_ptr<Dispatcher>;

        template <typename T>
        void registerHandler(MType mtype, const typename CallbackT<T>::MessageCallback &handler)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            auto cb = std::make_shared<CallbackT<T>>(handler);
            _handlers.insert(std::make_pair(mtype, cb));
        }

        void onMessage(const BaseConnection::ptr &conn, BaseMessage::ptr &msg)
        {
            // 找到消息类型对应的业务处理函数，进行调用即可
            std::unique_lock<std::mutex> lock(_mutex);
            auto it = _handlers.find(msg->mtype());
            if (it != _handlers.end())
            {
                return it->second->onMessage(conn, msg);
            }
            // 没有找到指定类型的处理函数--因为客户端和服务器都是我们自己设计的，因此不可能出现这种情况
            ELOG("收到未知类型的消息！");
            conn->shutdown();
        }

    private:
        std::mutex _mutex;
        std::unordered_map<MType, Callback::ptr> _handlers;
    };
}